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Comment: Changed wording for consistency.
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Comment: Changed example so method does not look static (Feedback from 2014-10-20).
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SDL_AndroidGetJNIEnv
Use this function to retrieve the Java native interface object (JNIEnv) of the current thread on Android builds.
Syntax
void* SDL_AndroidGetJNIEnv(void)
Return Value
Returns a pointer to Java native interface object (JNIEnv) to which the current thread is attached, or 0 on error.
Code Examples
// Calls the void showHome() method of the Java instance of MyActivity.
void showHome(void)
{
// retrieve the JNI environment.
JNIEnv* env = (JNIEnv*)SDL_AndroidGetJNIEnv();
// retrieve the Java instance of the SDLActivity
jobject activity = (jobject)SDL_AndroidGetActivity();
// find the Java class of the activity. It should be SDLActivity or a subclass of it.
jclass clazz(env->GetObjectClass(activity));
// find the identifier of the method to call
jmethodID method_id = env->GetMethodID(clazz, "showHome", "()V");
// effectively call the Java method
env->CallVoidMethod(activity, method_id);
// clean up the local references.
env->DeleteLocalRef(activity);
}
Remarks
The prototype of the function in SDL's code actually declare a void* return type, even if the implementation returns a pointer to a JNIEnv. The rationale being that it allows not to include jni.h in the headers of the SDL.
Version
This function is available since SDL 2.0.0.
